Brad
(1st for some reason I am still allowed on this forum to post so I will get in my comments before getting the boot of this board)
FB Extortion is almost imposible to prove to eBay such that they will act on it.
Essentially it is never considered FB Extortion when forcing you to give a refund or get negative FB. Nor is it to get you to first leave positive FB or get negative FB in return.
Generally the person must be threateneing you with negative FB to give him something that was not to be included in the acution such as he buys a pair of pants but threatens negative FB of you dont include a jacket for free.
The easiest way I look at whether FB extortion is something that eBay considers a violation is for any instance where eBay is loosing money.
In the case of a free jacket, had that been in your listing, then eBay would have gotten extra fees in the extra money that would have been bid towards the final sale.
So when examinig whether FB extortion is worthy of bringing up to eBay, just look at it the nature of what is being asked and determine if and how eBay would be loosing any additional fees they could have earned should you proceed and give in to the threat and not bill anything extra for it.
If eBay could have made money, it may be considered as FB extortion, however you must have written proof of the threats.
Malcolm